Raw data stored in piezo_data_points, and transferred to modelpoints for interpolation. Interpolated grids (8 m) generated for model extent using TopotoRaster function. The watertable elevation is stored as either GWL or watertableRL (m NZVD2016). Depth to water is stored in DTW, based on the 2021 LiDAR DEM. The extent of the area of interest is stored in modelling_extent. Layers are in NZTM (NZGD2000 EPSG: 2193) coordinates and NZVD2016 vertical datum (EPSG:7879)

The purpose of the New Zealand Geothermal Analytical Laboratory (NZGAL) Information Management System, is for recording and storing all information related to sample information and results pertaining to samples received by NZGAL. NZGAL contains: 1. Paper records relating to sample submission, client correspondence, sample treatment, measurement, results and internal operations documents (SOP’s and Quality Manual). 2. Digital database and associated files: QLIMS database. Digital database records for sample details pertaining to sample reception to measurement to results 2011 to present. Gas database. MS Access database for recording geothermal gas analysis and calculations 3. Internal digital and paper-based data relating to ongoing data quality control, measurement output and internal procedures. DOI: https://doi.org/10.21420/D539-T756 Cite as: GNS Science. (2021). New Zealand Geothermal Analytical Laboratory Information Management System (NZGAL) [Data set]. GNS Science. https://doi.org/10.21420/D539-T756

Dunedin City in the South Island of New Zealand has many assets and critical infrastructure sitting on a low-lying coastal plain that is underlain by a largely unseen and relatively poorly understood hazard. Shallow groundwater in this area limits the unsaturated ground available to store rain and runoff, promotes flooding and creates opportunities for infiltration into stormwater and wastewater networks. Groundwater levels are expected to rise as sea level rises, causing greater frequency of flooding and/or direct inundation once it nears the ground surface. This zipped archive contains ArcGIS 10.8 geodatabases and spatial analysis of data gathered from a shallow groundwater monitoring network between 6/3/2019 and 1/5/2023. Data are licenced under Creative Commons Attribution 4.0 (CC-BY-4.0) licence without warranty. A series of statistical surfaces represent the present-day (2023) water table elevation and depth to groundwater, the response to rainfall recharge and tidal forcing, the available subsurface storage of rain infiltration. Simple geometric models have also been developed using the present shape and position of the water table, combined with tidal fluctuations, to forecast the future state of groundwater levels at 10 cm increments of sea level rise (up to 1 m). The geometric models are strongly empirical, with many implicit assumptions and caveats – particularly, that they do not account for groundwater flow and possible changes in water-budget mass balance. Although many variables and controlling processes are simplified into a single parameter, the projected groundwater levels highlight how local variations in the water table shape and slope interact locally with the ground elevation or infrastructure networks. They are best considered as a worst-case analysis of groundwater-related contribution to hazard and how this will evolve over time. Further description of these data, and implications from the analysis, can be found in Cox et al. (2023) GNS Science Report 2023/43 doi:10.21420/5799-N894.

Grid and vector (poly) datasets representing a forecast state of groundwater in Dunedin under present (SLR=000) and future conditions of sea level rise (SLR=010, 020, 030 cm etc where [OFF] represents increments of changing sea level). Layers are in NZTM (NZGD2000 EPSG: 2193) coordinates, named using a convention where: GWL= groundwater level (m, NZVD2016 EPSG:7879); DTW = depth to groundwater (m, rel to ground LiDAR 2021); MED = condition at median level; p95 = condition at a high 95th percentile level; MHWS = condition at mean high water springs; ESL = condition at storm-tide of particular extreme sea level ARI; RAINstor = maximum possible subsurface storage of rainfall (in mm); [OFF] = an amount of sea level rise in 10cm increments; [ARI] = average recurrence interval of ESL in years; [AFI] = average recurrence interval of a particular 12hr rainfall exceedance in years. Polygons define either places where groundwater is emergent (DTW≤0) under a given forecast, or places where a rainfall depth at AFI exceeds the available subsurface storage (and any infiltration to groundwater should no longer be possible).